[ih] Larry Roberts & RD the first electronic mail manager software [was written in TECO on TENEX]

[the keyboard of geoff goodfellow]

"... In 1969 Roberts became director of the Information Processing
Techniques Office at ARPA. In 1971 he wrote one of the first e-mail
programs, RD, which for the first time allowed users to save, delete, and
organize their messages....
so sez:
https://www.britannica.com/biography/Lawrence-Roberts

while
https://cs.stanford.edu/people/eroberts/courses/soco/projects/1999-00/internet/email.html
 sez:

...The Rise of Email by way of Convenient Mail-Managers

Stephen Lukasik, one of ARPA's directors from 1971-75 might be one of the
most important advocates of email in its young age. He strongly encouraged
his staff to use email. It was even considered the most effective way to
reach Lukasik. Close friends and colleagues with Larry Roberts, Lukasik
confided to Roberts in 1973 that he was beginning to face problems
organizing the chaotic pile of messages received each day. (At this point,
in a study conducted by ARPA under Lukasik's direction discovered that 75%
of all ARPANET traffic was in the form of email.) Not to mention, reading
and responding to the messages was, as of yet not a simple matter. In
response, Roberts wrote the first "mail-manager software," RD. Its
functions included displaying a menu of messages and allowing the user to
file messages and delete messages. This inspired an outburst of variations
on the mail manager. A legendary variation, MSG was created in 1975 by John
Vittal. MSG quickly became the most widely used mail-management program due
to its convenient features. It could handle an even greater amount of mail
than RD, could sort messages into separate files, and most importantly,
reply and forward with much greater ease. MSG also spawned a large amount
of variations...

[any others?]

-- 
Geoff.Goodfellow at iconia.com
living as The Truth is True